Companies that use Slack for internal collaboration now have a new way to communicate. The startup began rolling out a voice calling feature on Wednesday that lets people talk to each other one-on-one or in group conference calls.

It’s a transition for Slack, which until now has focused mainly on text communication. The company revealed yesterday that allowing people to make calls is a big part of its roadmap for 2016, and this initial beta launch is a first step.

Right now, it's available to a subset of Slack users — the company told TechCrunch that less than half of all users have access — but administrators can check if it's available to them here.

When users are talking via direct message in the Slack apps for Mac and Windows or using Google Chrome, they'll be able to click on a handset icon to start an audio call with the person they're messaging.

Users get a pop-up notification that lets them pick up the call and start talking, or decline the call if they’d rather not accept it.

In a channel — a room full of people — callers are prompted to make sure they want to start a voice call, then asked to create a name for the call. After that, a message posts in the channel that allows up to 15 people to take part.

Once on a call, users can post emojis to show how they feel about what’s being discussed.

The good news is that users can’t start calling people willy-nilly; teams that don’t want to use Slack for voice communication can leave the setting turned off.

Looking forward, Slack is still waiting to provide voice calling to its mobile apps on iOS and Android, along with its Linux app.